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Abstract

Alveolar macrophages secrete numerous mediators, playing an important role in host defence. Among these mediators, nitric oxide (NO) and hydrogen peroxide (H2O2) are both involved in bactericidal killing and trigger the release of other cellular metabolites. We have analyzed the effect of an atmosphere polluted with ozone (0.03-0.5 ppm v/v) on the monocytic cell line THP-1, as a model for alveolar macrophages, in vitro. NO and H2O2 were chosen to evaluate cell response to ozone. Cell injury was evaluated using lactate dehydrogenase (LDH) liberation into the medium. An exposure to 0.5 ppm ozone proved to be more toxic to the cells, than 0.1 or 0.03 ppm, evidenced by more LDH being liberated and cytotoxicity reaching values up to 64%. For all ozone concentrations, H2O2 production reached a peak value after 10-15 min of exposure, after which the concentration of extracellular H2O2 production diminished rapidly. The highest NO concentrations were measured with 0.5 ppm ozone, reaching a maximum value of 1460 nmol/L per 5 x 10(6) cells, which is 1.55 times higher than for nonexposed cells. Lower concentrations barely induced higher NO concentrations compared to nonexposed cells. The results indicate that ozone effects not only the viability of human monocytes but also the release of antibacterial and defense signaling molecules and suggest that ozone-mediated cytotoxicity may be related to the secretion of NO and H2O2.

Cell death induced by ozone and various non-thermal plasmas: therapeutic perspectives and limitations

“…Furthermore, non-thermal plasma has been shown to produce considerable amounts of ozone 8 9 14 . It is well known that ozone is an extremely reactive gas and exposure to it results in acute cytotoxic effects 21 22 33 . For superficial cancer treatment and wound healing it is important to know the time and dose dependent effects of plasmas on pathogenic (cancerous) cells and healthy tissue.…”

“…As of yet, no comparative study has been thoroughly performed that observes the effects of different chemical compositions of plasma on the physiological functions of the cells. Moreover, non-thermal plasma is capable of producing significant amounts of ozone 8 9 , which is known to have very aggressive effects on cells 21 22 . However, the information concerning comparison of the biological effects of non-thermal plasma and ozone are basically lacking.…”

Responses of Solid Tumor Cells in DMEM to Reactive Oxygen Species Generated by Non-Thermal Plasma and Chemically Induced ROS Systems

“…Many evidences from recent review of literature supported that plasma-induced ROS and RNS effectively kills many types of cancer cells 9 10 11 12 13 , and also showed antitumor potential in vivo 10 13 . Reported work also suggests that non-thermal plasma is capable of producing significant amounts of ozone (O 3 ) 14 15 , which is known to have very aggressive effects on cells 16 . Oleg et al also claimed role of various plasma and O 3 in cell death 17 .…”

The antiproliferative effects of cold atmospheric plasma‐activated media on different cancer cell lines, the implication of ozone as a possible underlying mechanism

“…Based on recent reports, ozone produced by CAP may also play an important role in the induction of anticancer effects of CAP (A. Fridman, Chirokov, & Gutsol, ; Tian & Kushner, ). It has been well documented that O 3 can demonstrate aggressive effects on cells (Klestadt, Laval‐Gilly, & Falla, ). For instance, Lunov et al () have demonstrated the role of O3 in the induction of cell death.…”